Our aim is to analyze endocrine and other control mechanisms that regulate insect development and to examine the possibility of using growth regulators and their analogues as safe insecticides to control pests and disease vectors. We have devised new approaches to insect endocrinology by using genetic mutants and techniques in the fruitfly Drosophila. We are analzing several mutants which appear to have endocrine defects and are attempting to isolate temperature-sensitive alleles of such mutations. We also plan to use segmental aneuploids to locate the structural genes for the enzymes involved in the synthesis and breakdown of several insect hormones, to produce mutations affecting these enzymes and analyze their effects on the phenotype. This combined use of genetics, biochemistry and insect physiology should permit a new kind of analysis of complex endocrine mechanisms. We shall also analyze nonharmonal factors regulating insect growth. We have evidence that a key factor in regulating growth in different parts of an organ like an imaginal disc is positional information, i.e., the information which cells have about their location in the organ. We shall investigate the mechanism whereby adjacent cells interact to control the growth of the tissue. These experiments may provide some new insights into intercellular communications and perhaps disclose a group of new agents that regulate insect growth. We are also interested in the use of insect hormone analogues, such as ecdysones and juvenile analogues, as safe insecticides. In this connection, we are examining the effects of insect hormones on the isopod crustacean, Armadillidium. We are also examining the endocrine control of molting and reproduction in Armadillidium. In addition to gaining new insights into comparative endocrinology, we hope to learn how organisms besides insects may be affected by analogues of insect hormones.